Association of TMEM106B Gene Polymorphism With Age at Onset in Granulin Mutation Carriers and Plasma Granulin Protein Levels

Department of Psychiatry, Washington University School of Medicine, 660 S Euclid Avenue, St Louis, MO 63110, USA.
Archives of neurology (Impact Factor: 7.42). 05/2011; 68(5):581-6. DOI: 10.1001/archneurol.2010.350
Source: PubMed


To test whether rs1990622 (TMEM106B) is associated with age at onset (AAO) in granulin (GRN) mutation carriers and with plasma GRN levels in mutation carriers and healthy, elderly individuals. Rs1990622 (TMEM106B) was identified as a risk factor for frontotemporal lobar degeneration with TAR DNA-binding protein inclusions (FTLD-TDP) in a recent genome-wide association.
Rs1990622 was genotyped in GRN mutation carriers and tested for association with AAO using the Kaplan-Meier method and a Cox proportional hazards model.
Alzheimer's Disease Research Center. Subjects We analyzed 50 affected and unaffected GRN mutation carriers from 4 previously reported FTLD-TDP families (HDDD1, FD1, HDDD2, and the Karolinska family). The GRN plasma levels were also measured in 73 healthy, elderly individuals.
Age at onset and GRN plasma levels.
The risk allele of rs1990622 was associated with a mean decrease of the AAO of 13 years (P = 9.9 × 10(-7)) and with lower plasma GRN levels in both healthy older adults (P = 4 × 10(-4)) and GRN mutation carriers (P = .0027). Analysis of the HapMap database identified a nonsynonymous single-nucleotide polymorphism rs3173615 (T185S) in perfect linkage disequilibrium with rs1990622.
The association of rs1990622 with AAO explains, in part, the wide range in the AAO of disease among GRN mutation carriers. We hypothesize that rs1990622 or another variant in linkage disequilibrium could act in a manner similar to APOE in Alzheimer disease, increasing risk for disease in the general population and modifying AAO in mutation carriers. Our results also suggest that genetic variation in TMEM106B may influence risk for FTLD-TDP by modulating secreted levels of GRN.

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    • "The human linkage of FTLD-TDP risk to TMEM106B allele suggests that T185S variation plays a role. While this genetic variation alters PGRN levels in serum (Cruchaga et al., 2011; Finch et al., 2011), the effect may be direct or indirect. Tissue culture studies reveal either small or no effect of TMEM106B variants on PGRN levels (Brady et al., 2013; Lang et al., 2012). "
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